use func_num_args() and func_get_args():
PHP Code:
function foo()
{
$numargs = func_num_args();
echo "this function was passed $numargs";
$arg_list = func_get_args();
for ($i = 0; $i < $numargs; $i++) {
echo "Argument $i is: " . $arg_list[$i] . "<br />\n";
}
}
foo(1, 2, 3);